Remember the insane shopping spree Ray J went on for his 38th birthday? Turns out, he didn't stop with treating himself to a brand new Maybach and Lincoln -- he also splurged on a classic car ... for a good cause,

Mac Miller would've turned 27 on Saturday, and one very important person in his life definitely didn't forget the occasion ... Ariana Grande. Mac's ex paid tribute to the late MC on social media just after the clock struck 12 on what would've been his next birthday. She tweeted at 12:13 AM ... "miss u."